Fight Over Voter Data Roils Democrats Ahead of Election

The party is trying to catch up with Republican efforts to collect and store voter data

WASHINGTON—Democrats are in a deepening internal battle over voter data seen as key in helping get out the vote ahead of looming 2020 presidential elections, correspondence reviewed by The Wall Street Journal shows.

The party is struggling to catch up with Republican efforts to collect and store voter data that allows politicians to directly target their voter outreach. But a growing battle between the Democratic National Committee and state parties about how to handle the process is threatening the party’s unity as the primary...